C++ named requirements: UnformattedInputFunction

 

C++

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Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

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Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

C++ named requirements

Basic
DefaultConstructible CopyAssignable CopyConstructible	MoveAssignable (C++11) MoveConstructible (C++11) Destructible
Type properties
ScalarType TriviallyCopyable (C++11) StandardLayoutType (C++11)	PODType TrivialType (C++11) ImplicitLifetimeType (C++20)
Library-Wide
EqualityComparable LessThanComparable Swappable (C++11) ValueSwappable (C++11) NullablePointer (C++11) Hash (C++11)	Allocator FunctionObject Callable Predicate BinaryPredicate Compare
Container
Container SequenceContainer ContiguousContainer (C++17) ReversibleContainer	AssociativeContainer AllocatorAwareContainer UnorderedAssociativeContainer (C++11)
Container Elements
DefaultInsertable (C++11) CopyInsertable (C++11) MoveInsertable (C++11)	EmplaceConstructible (C++11) Erasable (C++11)
Iterator
LegacyIterator LegacyOutputIterator LegacyInputIterator LegacyForwardIterator	LegacyBidirectionalIterator LegacyRandomAccessIterator LegacyContiguousIterator (C++17) ConstexprIterator (C++20)
Stream I/O
FormattedInputFunction UnformattedInputFunction	FormattedOutputFunction UnformattedOutputFunction
Formatting
BasicFormatter (C++20)	Formatter (C++20)
Random Numbers
SeedSequence (C++11) RandomNumberEngine (C++11)	RandomNumberDistribution (C++11) UniformRandomBitGenerator (C++11) RandomNumberEngineAdaptor (C++11)
Concurrency
BasicLockable (C++11) Lockable (C++11) TimedLockable (C++11) SharedLockable (C++14) SharedTimedLockable (C++14)	Mutex (C++11) TimedMutex (C++11) SharedMutex (C++17) SharedTimedMutex (C++14)
Other
CharTraits RegexTraits (C++11) BitmaskType NumericType LiteralType (C++11)	UnaryTypeTrait (C++11) BinaryTypeTrait (C++11) TransformationTrait (C++11) Clock (C++11) TrivialClock (C++11)

 

Requirements

An UnformattedInputFunction is a stream input function that performs the following:

• Constructs an object of type basic_istream::sentry with automatic storage duration and with the noskipws argument set to true, which performs the following

• if eofbit or badbit are set on the input stream, sets the failbit as well, and if exceptions on failbit are enabled in this input stream's exception mask, throws ios_base::failure.
• flushes the tie()'d output stream, if applicable

• Checks the status of the sentry by calling sentry::operator bool(), which is equivalent to basic_ios::good.
• If the sentry returned false or sentry's constructor threw an exception:

• sets the number of extracted characters (gcount) in the input stream to zero
• if the function was called to write to an array of CharT, writes CharT() (the null character) to the first location of the array

• If the sentry returned true, performs the input as if by calling rdbuf()->sbumpc() or rdbuf()->sgetc().

• if the end of the stream is reached (the call to rdbuf()->sbumpc() or rdbuf()->sgetc() returns Traits::eof()), sets eofbit. If exceptions on eofbit are enabled in this stream's exception mask, throws ios_base::failure.
• if an exception is thrown during input, sets badbit in the input stream. If exceptions on badbit are enabled in this stream's exception mask, the exception is also rethrown.
• If no exception was thrown during input, sets the number of extracted characters (gcount) in the input stream.

• In any event, whether terminating by exception or returning, the sentry's destructor is called before leaving this function.

Standard library

The following standard library functions are UnformattedInputFunctions.

• std::getline, except that it does not modify gcount.
• basic_istream::operator>>(basic_streambuf*)
• basic_istream::get
• basic_istream::getline
• basic_istream::ignore
• basic_istream::peek
• basic_istream::read
• basic_istream::readsome
• basic_istream::putback, except that it first clears eofbit
• basic_istream::unget, except that it first clears eofbit
• basic_istream::sync, except that it does not modify gcount
• basic_istream::tellg, except that it does not modify gcount
• basic_istream::seekg, except that it first clears eofbit and does not modify gcount
• std::ws, except that it does not modify gcount